DateUtils: move event details formatting to DateUtils

Also do not display seconds, because it is not
meaningful and is not selected in date picker.

app/src/main/java/it/danieleverducci/lunatracker/MainActivity.kt

@@ -41,7 +41,6 @@ import okio.IOException
 import org.json.JSONException
 import utils.DateUtils
 import utils.NumericUtils
-import java.text.DateFormat
 import java.util.Calendar
 import java.util.Date
 
@@ -360,7 +359,6 @@ class MainActivity : AppCompatActivity() {
     fun showEventDetailDialog(event: LunaEvent, items: ArrayList<LunaEvent>) {
         // Do not update list while the detail is shown, to avoid changing the object below while it is changed by the user
         pauseLogbookUpdate = true
-        val dateFormat = DateFormat.getDateTimeInstance()
         val d = AlertDialog.Builder(this)
         d.setTitle(R.string.dialog_event_detail_title)
         val dialogView = layoutInflater.inflate(R.layout.dialog_event_detail, null)
@@ -372,8 +370,9 @@ class MainActivity : AppCompatActivity() {
 
         val currentDateTime = Calendar.getInstance()
         currentDateTime.time = Date(event.time * 1000)
+
         val dateTextView = dialogView.findViewById<TextView>(R.id.dialog_event_detail_type_date)
-        dateTextView.text = String.format(getString(R.string.dialog_event_detail_datetime_icon), dateFormat.format(currentDateTime.time))
+        dateTextView.text = String.format(getString(R.string.dialog_event_detail_datetime_icon), DateUtils.formatDateTime(event.time))
         dateTextView.setOnClickListener {
             // Show datetime picker
             val startYear = currentDateTime.get(Calendar.YEAR)
@@ -386,11 +385,9 @@ class MainActivity : AppCompatActivity() {
                 TimePickerDialog(this, { _, hour, minute ->
                     val pickedDateTime = Calendar.getInstance()
                     pickedDateTime.set(year, month, day, hour, minute)
-                    currentDateTime.time = pickedDateTime.time
-                    dateTextView.text = String.format(getString(R.string.dialog_event_detail_datetime_icon), dateFormat.format(currentDateTime.time))
-
                     // Save event and move it to the right position in the logbook
-                    event.time = currentDateTime.time.time / 1000 // Seconds since epoch
+                    event.time = pickedDateTime.time.time / 1000 // Seconds since epoch
+                    dateTextView.text = String.format(getString(R.string.dialog_event_detail_datetime_icon), DateUtils.formatDateTime(event.time))
                     logbook?.sort()
                     recyclerView.adapter?.notifyDataSetChanged()
                     saveLogbook()

app/src/main/java/utils/DateUtils.kt

@@ -1,12 +1,17 @@
 package utils
 
 import android.content.Context
+import android.os.Build
 import android.text.format.DateFormat
 import it.danieleverducci.lunatracker.R
 import java.util.Date
 
 class DateUtils {
     companion object {
+        /**
+         * Format time duration in seconds as e.g. "2 hours, 1 min".
+         * Used for the duration to the next/previous event in the event details dialog.
+         */
         fun formatTimeDuration(context: Context, secondsDiff: Long): String {
             var seconds = secondsDiff
 
@@ -65,7 +70,8 @@ class DateUtils {
         }
 
         /**
-         * Formats the provided unix timestamp in a string like "3 hours, 26 minutes ago)
+         * Formats the provided unix timestamp in a string like "3 hours, 26 minutes ago".
+         * Used for the event list.
          */
         fun formatTimeAgo(context: Context, unixTime: Long): String {
             val secondsDiff = (System.currentTimeMillis() / 1000) - unixTime
@@ -100,5 +106,21 @@ class DateUtils {
             }
             return formattedTime.toString()
         }
+
+        /**
+         * Format time as localized string without seconds. E.g. "Sept 18, 2025, 03:36 PM".
+         * Used in the event detail dialog.
+         */
+        fun formatDateTime(unixTime: Long): String {
+            val date = Date(unixTime * 1000)
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+                val dateFormat = android.icu.text.DateFormat.getDateTimeInstance(android.icu.text.DateFormat.RELATIVE_SHORT, android.icu.text.DateFormat.SHORT)
+                return dateFormat.format(date)
+            } else {
+                // fallback
+                val dateFormat = java.text.DateFormat.getDateTimeInstance()
+                return dateFormat.format(date)
+            }
+        }
     }
 }